Manufacturing tolerances

The production of printed circuit boards is carried out according to the valid IPC guidelines and standards and on the basis of following technical specifications. HDI or MFT boards can be produced with smaller tolerances. Differing requirements of the customer must be explicitly agreed!

Pattern tolerances

The hole pattern for vias (DK) goes through all the layers of the circuit and therefore serves as a location reference for the other patterns.

TypeTolerance
TypeDrilling pattern (PTH) to conductive pattern outer layersTolerance±0,10mm
TypeDrilling pattern (PTH) to conductive pattern inner layers Tolerance±0,15mm
TypeDrilling pattern (PTH) to milling pattern / contourTolerance±0,10mm
TypeDrilling pattern (NPTH) to milling pattern / contourTolerance±0,10mm
TypeDrilling pattern (PTH) to marking printTolerance±0,15mm
Type Tolerance 
TypeConductive pattern to solder resistTolerance±0,10mm
TypeConductive pattern to marking printTolerance±0,20mm
Type Tolerance 
TypeHole to hole, one pass* (PTH-PTH or NPTH-NPTH)Tolerance±0,05mm
TypeHole to hole, two passes (PTH-NPTH)Tolerance±0,10mm

* Also applies for PTH-NPTH if they are drilled in one run (e.g. location holes for SMD stencils).

Vias & Drills

TypeSurfaceFinal-Ø
TypePlated-through-holes (PTH) and component holesSurfaceHAL surfaceFinal-ر0,10mm
Type Surfacechem. surface Final-ر0,05mm
TypeNon-plated-through-holes (NPTH)Surface-Final-ر0,08mm

Cu thickness in vias

Via typeClass 2 (standard)class 3
Via typeVia (> 150µm)Class 2 (standard)min. 20µm - 25µmclass 3min. 20µm - 25µm
Via typeMicrovia (≤ 150µm)Class 2 (standard)min. 18µm - 20µmclass 3min. 20µm - 25µm
Via typeBlind ViaClass 2 (standard)min. 10µm - 12µmclass 3min. 10µm - 12µm
Via typeBuried ViaClass 2 (standard)min. 10µm - 12µmclass 3min. 10µm - 12µm

Conductor

TypeToleranceReference
TypeConductor width*Tolerancemin. 80%Referencein comparsion to the data
TypeConductor space*Tolerancemax. 30% reduction (standard)Referencein comparsion to the data

*acc. to IPC-6012C

Impedance control

TypeTolerance Mode
TypeImpedance controlTolerance 10%Modenormal
TypeImpedance controlTolerance 5%Modeextended

Milling

TypeTolerance
TypeMilling offsetTolerance±0,10mm
TypeZ-Axis milling depthTolerance±0,20mm

Scoring

TypeTolerance
TypeOffset (to PCB center)Tolerance±0,10mm
TypeDrilling pattern (PTH) to scoring patternTolerance±0,15mm
TypeDrilling pattern (NPTH) to scoring patternTolerance±0,20mm
TypePCB dimension x/yTolerance±0,15mm
TypeScoring depthTolerance±0,20mm

Base material - rigid PCBs

TypeTolerance
TypeBase material thicknessTolerance±10%

The information about the base material thickness exclusively defines the thickness of the dielectric including base copper. The other layer structures such as electroplated Cu layers or solder resist layers result in increased final thickness.

Base material - flexible PCBs

TypeTolerance
TypeDielectric thickness ≥ 0,075mmTolerance±10%
Type0,025mm ≤ Dielectric thickness ≥ 0,075mmTolerance±10%
Type0,020mm ≤ Dielectric thickness ≥ 0,025mmTolerance±12,5%
TypeDielectric thickness < 0,020mmTolerance±15%
Type Tolerance 
TypeAdhesive thickness ≥ 0,075mmTolerance±10%
Type0,025mm ≤ Adhesive thickness ≥ 0,075mmTolerance±15%
Type0,020mm ≤ Adhesive thickness ≥ 0,025mmTolerance±20%
TypeAdhesive thickness < 0,020mmTolerance±30%
TypeFor woven or combinations with woven stiffener:
Adhesive thickness ≥ 0,025mm
Tolerance±20%

Specifications according to IPC-4204A. The information on the thickness of the base material defines solely the dielectric thickness or adhesive thickness incl. base copper. The other layer structures such as e.g. galvanic Cu or solder-stop lead to an increased circuit final thickness.

Rigid PCB thickness

TypeTolerance
TypeProducibility level B (standard)ToleranceThe higher value of ±10% or ±178µm

Thickness tolerances for pressed multilayers according to IPC-2222A. When measured over metallizations or coatings, those thicknesses and tolerances must be considered.

Flexible PCB thickness

TypeTolerance
TypeFlexible part thickness Tolerance±50µm
TypeFlexible part + stiffener thickness Tolerance±100µm

Bow & Twist

For PCBs ≥ 0,8mm thicknessTolerance
For PCBs ≥ 0,8mm thicknesswith SMDTolerance0,75%
For PCBs ≥ 0,8mm thicknesswithout SMDTolerance1,50%

Please note that the twist & bow value is increased above average, if the copper balance of the PCB is locally very unequal or if the circuit board is very thin.

Surfaces

Solder-stop

TypeCoating thickness
TypeOn the PCB Coating thickness > 10µm < 25µm
TypeOn the conductor edgeCoating thickness> 5µm < 25µm

Dielectric strength min. 500V DC.

Delivery quantity

TypeTolerance
TypeExcess or short delivery of up toTolerance10%